Circuit breaker and method

Abstract

A circuit breaker protects an electric low-voltage circuit, and has the function of ascertaining a level of the current of the low-voltage circuit. A mechanical separating contact unit is operated using a mechanical handle such that an opening function of contacts is switched to prevent a current flow or a closing function of the contacts is switched for a current flow in the low-voltage circuit. An electronic interruption unit is connected to the mechanical separating contact unit in series on the circuit side and which, as a result of semiconductor-based switch elements, has a high-ohmic state of the switch elements to prevent a current flow and a low-ohmic state of the switch elements for a current flow in the low-voltage circuit. The ascertained current level is compared with current thresholds and if the current thresholds are exceeded, a process for preventing the current flow in the low-voltage circuit is initiated.

1 - 17 . (canceled) 
     
     
         18 . A circuit breaker device for protecting an electrical low-voltage circuit, the circuit breaker device comprising:
 a housing having network-side and load-side connections for conductors of the electrical low-voltage circuit;   a voltage sensor for ascertaining a level of a voltage of the electrical low-voltage circuit;   a current sensor for ascertaining a level of a current of the electrical low-voltage circuit;   a mechanical isolating contact able to be operated using a mechanical handle and having contacts, with a result that opening of said contacts prevent a current flow or closing of said contacts for the current flow in the electrical low-voltage circuit is able to be switched;   an electronic interruption unit connected in series with said mechanical isolating contact on a circuit side and having semiconductor-based switching elements, as a result of said semiconductor-based switching elements, said electronic interruption unit has a high-impedance state of said semiconductor-based switching elements to prevent the current flow and a low-impedance state of said semiconductor-based switching elements for the current flow in the electric low-voltage circuit;   a controller connected to said voltage sensor, to said current sensor, to said mechanical isolating contact and to said electronic interruption unit, wherein if the current and/or current-time limit values is/are exceeded a process for preventing the current flow in the electrical low-voltage circuit is initiated; and   the circuit breaker device is configured such that a user of the circuit breaker device operates said mechanical handle in order to close said contacts, wherein said electronic interruption unit is in the high-impedance state, in that, after said contacts have been closed, said electronic interruption unit goes to the low-impedance state only if a checking function allows the low-impedance state of said semiconductor-based switching elements.   
     
     
         19 . The circuit breaker device according to  claim 18 , further comprising a display for displaying information and is connected to said controller, wherein said display displays a state of said semiconductor-based switching elements of said electronic interruption unit and/or a position of said contacts of said mechanical isolating contact. 
     
     
         20 . The circuit breaker device according to  claim 18 , wherein the checking function contains a self-test of a functionality of the circuit breaker device, during which at least one component of a unit of the circuit breaker device is checked, and if the at least one component of the unit is functional, the low-impedance state is allowed. 
     
     
         21 . The circuit breaker device according to  claim 20 , wherein in an absence of the functionality, said contacts of said mechanical isolating contact are opened. 
     
     
         22 . The circuit breaker device according to  claim 20 , wherein the functionality of said electronic interruption unit is checked in order to determine whether said semiconductor-based switching elements are functional. 
     
     
         23 . The circuit breaker device according to  claim 20 , wherein:
 said voltage sensor is checked with regard to its functionality for ascertaining the level of the voltage; and/or   said current sensor is checked with regard to its functionality for ascertaining the level of the current.   
     
     
         24 . The circuit breaker device according to  claim 18 , wherein
 the checking function carries out a check of at least one of the following parameters:   checking whether a first overvoltage value and/or a second overvoltage value and/or a third overvoltage value is/are exceeded;   checking whether a first undervoltage value is undershot;   checking whether a first temperature limit value and/or a second temperature limit value and/or a third temperature limit value is/are exceeded; and   checking parameters of said load-side connection, including whether a load-side first and/or second resistance value or a load-side first and/or second impedance value is/are undershot.   
     
     
         25 . The circuit breaker device according to  claim 24 , wherein:
 if the first overvoltage value is exceeded overvoltage information is emitted;   if the second overvoltage value is exceeded said electronic interruption unit goes to the high-impedance state;   if the third overvoltage value is exceeded said contacts are opened;   if the first undervoltage value is undershot undervoltage information is emitted or/and said electronic interruption unit remains in the high-impedance state;   if the first temperature limit value is exceeded temperature information is emitted;   if the second temperature limit value is exceeded said electronic interruption unit goes to the high-impedance state;   if the third temperature limit value is exceeded said contacts are opened;   if the load-side first resistance value or the load-side first impedance value is undershot impedance information is emitted; and   if the load-side second resistance value or the load-side second impedance value is undershot said electronic interruption unit remains in the high-impedance state.   
     
     
         26 . The circuit breaker device according to  claim 24 , wherein the checking function carries out a check of at least one of the parameters continuously. 
     
     
         27 . The circuit breaker device according to  claim 18 , wherein:
 in a case of a connected said mechanical isolating contact and said electronic interruption unit has the low-impedance state, and:
 in a case of an ascertained current exceeding a first current threshold value, said electronic interruption unit goes to the high-impedance state and said mechanical isolating contact remains closed; 
 in a case of the ascertained current exceeding a second current threshold value, said electronic interruption unit goes to the high-impedance state and said mechanical isolating contact is opened; and 
 in a case of the ascertained current exceeding a third current threshold value, said electronic interruption unit goes to the high-impedance state and said mechanical isolating contact is opened. 
   
     
     
         28 . The circuit breaker device according to  claim 18 , wherein the circuit breaker device is configured such that said contacts of said mechanical isolating contact can be opened, but not closed, by said controller. 
     
     
         29 . The circuit breaker device according to  claim 18 , further comprising a differential current sensor for ascertaining differential currents in the electrical low-voltage circuit. 
     
     
         30 . The circuit breaker device according to  claim 18 , wherein the circuit breaker device is configured such that position information relating to said contacts is ascertained, and is transmitted to said controller. 
     
     
         31 . The circuit breaker device according to  claim 18 , wherein the checking function contains a self-test of a functionality of the circuit breaker device, during which a plurality of components of a plurality of units, of the circuit breaker device are checked, and if at least one component of the plurality of components, of the plurality of units, is functional, the low-impedance state is allowed. 
     
     
         32 . The circuit breaker device according to  claim 18 , wherein:
 in a case of a connected said mechanical isolating contact and said electronic interruption unit has the low-impedance state, and:
 in a case of an ascertained current exceeding a first current threshold value for a first period of time, said electronic interruption unit goes to the high-impedance state and said mechanical isolating contact remains closed; 
 in a case of the ascertained current exceeding a second current threshold value for a second period of time, said electronic interruption unit goes to the high-impedance state and said mechanical isolating contact is opened; and 
 in a case of the ascertained current exceeding a third current threshold value, said electronic interruption unit goes to the high-impedance state and said mechanical isolating contact is opened. 
   
     
     
         33 . The circuit breaker device according to  claim 24 , wherein the checking function carries out a check of all of the parameters continuously, and if a respective one of the parameters is no longer exceeded or undershot, a low-impedance state of said semiconductor-based switching elements is allowed, if said contacts were not opened. 
     
     
         34 . A method for a circuit breaker device for protecting an electrical low-voltage circuit, which comprises the steps of:
 ascertaining a level of a current of the electrical low-voltage circuit;   operating a mechanical isolating contact using a mechanical handle, with a result that opening of contacts to prevent a current flow or closing of the contacts for the current flow in the electrical low-voltage circuit can be switched;   setting an impedance of an electronic interruption unit which is connected in series with the mechanical isolating contact on a circuit side and which, as a result of semiconductor-based switching elements, has a high-impedance state of the semiconductor-based switching elements in order to prevent the current flow and a low-impedance state of the semiconductor-based switching elements for the current flow in the electrical low-voltage circuit;   comparing an ascertained level of the current with current and/or current-time limit values and if the current and/or current-time limit values are exceeded a process for preventing the current flow in the electric low-voltage circuit is initiated; and   operating, via a user of the circuit breaker device, the mechanical handle in order to close the contacts, wherein the electronic interruption unit initially in the high-impedance state, and that, after the contacts have been closed, the electronic interruption unit goes to the low-impedance state only if a checking function allows the low-impedance state of the semiconductor-based switching elements.   
     
     
         35 . A non-transitory computer program comprising computer executable instructions for carrying out the method according to  claim 34 . 
     
     
         36 . A non-transitory computer-readable storage medium having computer executable instructions for performing the method according to  claim 34 .